Aspect Ratio Calculator
Calculate dimensions and find the exact aspect ratio for images and video.
Calculated Ratio
16:9
Original Dimensions
Scaled Dimensions
What is this tool?
The Aspect Ratio Calculator calculates proportional dimensions and reduces pixel measurements to simplified aspect ratios (such as 16:9, 4:3, or 1:1). It uses Greatest Common Divisor (GCD) reduction on your input width and height, then lets you scale either dimension to calculate the corresponding scaled width or height automatically without distortion.
How to calculate and scale aspect ratios
- Enter your original width and height in the Original Dimensions box.
- Review the simplified aspect ratio displayed in the summary banner.
- In the Scaled Dimensions section, enter your target width or height.
- The calculator automatically updates the opposite dimension to preserve the exact ratio.
Key Features
- Automatic Greatest Common Divisor (GCD) ratio reduction
- Bidirectional scale calculation (adjust width or height dynamically)
- Instant real-time calculations as you type
- Zero external network requests or server tracking
Frequently Asked Questions
What is an aspect ratio?
An aspect ratio is the proportional relationship between the width and height of an image, video, or screen display, typically written as two integers separated by a colon (such as 16:9 or 4:3).
How do I calculate a scaled dimension without stretching?
Enter your original dimensions to establish the baseline ratio, then enter either your new target width or height. The tool multiplies by the ratio factor to give you the exact matching dimension.
What are standard video and display aspect ratios?
Standard aspect ratios include 16:9 (modern widescreen monitors, HDTV, and YouTube), 9:16 (vertical mobile video such as TikTok, Reels, and Shorts), 4:3 (classic video and photography), and 1:1 (square social media photos).
Is my dimensional data transmitted to a server?
No. All calculations are executed completely inside your browser using client-side JavaScript. No data is sent over the network.
Privacy First
Calculated entirely within your browser memory. No dimensions or data are sent to any server.